1. Field of the Invention
The present invention relates to a reciprocating drive device for reciprocating a drive member by transmitting a rotating force from a motor to a regulator having a driven gear meshing with a drive gear fixed outside a housing of the motor. More particularly, the present invention relates to a relative-movement preventing unit of the reciprocating drive device for preventing a relative movement between the housing and a support base for supporting the driven gear.
2. Description of Related Art
A power window device shown in FIGS. 9A-10 is one type of a reciprocating drive device. The power window device includes a motor 1 and an X-arm type regulator 2. The regulator 2 includes a support base 3 fixed to a vehicle door, a lift arm 5 pivotally supported on the support base 3 by a support shaft 17, a sector gear 4 integrally joined to the lift arm 5, an equalizer arm 6 pivotally linked to the lift arm 5, an equalizer bracket 7 for guiding a movement of a lower end of the equalizer arm 6, and a lift arm bracket 8 for guiding movements of an upper end of the equalizer arm 6 and an upper end of the lift arm 5.
FIG. 10 shows an internal construction of an output part 10 of the motor 1. A worm 11 fixed to an output shaft (not shown) of a motor body portion 9 of the motor 1 meshes with a worm wheel 15 fixed to an output shaft 14 in a space enclosed by a housing 12 and a cover 13 of the output part 10. Rotating force from the motor body portion 9 is transmitted to the sector gear 4 through the worm 11, the worm wheel 15, the output shaft 14 and a driving gear 16 fixed to the output shaft 14, and the sector gear 4 turns around the support shaft 17. When the sector gear 4 turns around the support shaft 17, the lift arm bracket 8 moves up or down and a window glass (not shown) mounted on the lift arm bracket 8 moves up or down.
The housing 12 is fixed to the support base 3 by a number of screws 18. In a lock state where the window glass has reached the top of a window frame when the window is fully closed or where the regulator has reached a lower limit when the window is fully open, the housing 12 tries to move with respect to the support base 3 in a direction perpendicular to the output shaft 14. To prevent a relative movement between the motor 1 and the support base 3, it is necessary for the housing 12 to be fixed to the support base 3 strongly. To this end, in this related art device, metal inserts 19 are embedded in the housing 12 which is made of relatively soft synthetic resin, and the screws 18 are screwed into these metal inserts 19.
However, the metal inserts 19 are expensive, and furthermore a troublesome insert-molding process for embedding the metal inserts 19 into the housing 12 is necessary.